Fossil Monkeys 127 
apes. Let us consider for a little the more essential additions to our 
knowledge since the publication of The Descent of Man. 
Since that time our knowledge of animal embryos has increased 
enormously. While Darwin was obliged to content himself with 
comparing a human embryo with that of a dog, there are now avail- 
able the youngest embryos of monkeys of all possible groups (Orang, 
Gibbon, Semnopithecus, Macacus), thanks to Selenka’s most successful 
tour in the East Indies in search of such material. We can now compare 
corresponding stages of the lower monkeys and of the Anthropoid 
apes with human embryos, and convince ourselves of their great 
resemblance to one another, thus strengthening enormously the 
armour prepared by Darwin in defence of his view on man’s nearest 
relatives. It may be said that Selenka’s material fills up the blanks 
in Darwin’s array of proofs in the most satisfactory manner. 
The deepening of our knowledge of comparative anatomy also 
gives us much surer foundations than those on which Darwin was 
obliged to build. Just of late there have been many workers in the 
domain of the anatomy of apes and lemurs, and their investigations 
extend to the most different organs. Our knowledge of fossil apes 
and lemurs has also become much wider and more exact since 
Darwin’s time: the fossil lemurs have been especially worked up 
by Cope, Forsyth Major, Ameghino, and others. Darwin knew very 
little about fossil monkeys. He mentions two or three anthropoid apes 
as occurring in the Miocene of Europe’, but only names Dryopithecus, 
the largest form from the Miocene of France. It was erroneously 
supposed that this form was related to Hylobates. We now know 
not only a form that actually stands near to the gibbon (Pliopi- 
thecus), and remains of other anthropoids (Pliohylobates and the 
fossil chimpanzee, Palaeopithecus), but also several lower catarrhine 
monkeys, of which Mesopithecus, a form nearly related to the modern 
Sacred Monkeys (a species of Semnopithecus) and found in strata of the 
Miocene period in Greece, is the most important. Quite recently, too, 
Ameghino’s investigations have made us acquainted with fossil monkeys 
from South America (Anthropops, Homunculus), which, according to 
their discoverer, are to be regarded as in the line of human descent. 
What Darwin missed most of all—intermediate forms between 
apes and man—has been recently furnished. E. Dubois, as is well 
known, discovered in 1893, near Trinil in Java, in the alluvial 
deposits of the river Bengawan, an important form represented by 
a skull-cap, some molars, and a femur. His opinion—much disputed 
as it has been—that in this form, which he named Pithecanthropus, 
he has found a long-desired transition-form is shared by the present 
writer. And although the geological age of these fossils, which, 
1 Descent of Man, p. 240. 
